DE4413489 shows an instrument for irradiating gynecological tumors where irradiation positions are realized by a central catheter which is introduced into the uterus, and two laterally pivotable catheters at whose ends the so-called ovoids have been provided and which are pressed against the cervix, are pushed apart at the front of the cervix. The applicator can be connected to a so-called remote afterloading machine which, via tubes, moves a radioactive source to an irradiation position in the tubes. The applicator usually comprises multiple tubes with two ovoids (egg-shaped spacers) on the two outer tubes, which ensure that the irradiation doses on the surface remain below the permissible limit. Alternatively, a so-called ring applicator tube can be used, whereby around the cervix a ring-shaped tube is applied in which a radioactive source can be moved and a dosed radiation delivery is possible. Irradiation is performed by bringing a radiation source, provided at the end of a guide cable via a guide tube and the catheter, in a desired position and allowing it to deliver radiation there for a predetermined length of time to attack the tumor.
Such applicators are often too large to allow insertion in an assembled condition and are therefore provided tube by tube and fixed by means of a screw clamp. Additionally, then, in the apparatus, in the direction of the large intestine and in the direction of the bladder, the interspace is stuffed with gauze. This is a laborious process and possibly painful and uncomfortable and often done under anesthesia which moreover is carried out differently by different doctors, which may adversely affect the success of the medical procedure.
This method accordingly has disadvantages associated with it because it depends on the skills of the medical staff whether it will yield an optimum result. Because the positioning of the central intrauterine tube and other tubes (in particular the colpostats or the ring applicator tube) may shift relative to each other, this entails risks for the patient, also because the bladder and the large intestine may thus be exposed to excessive radiation.